Long-term prognosis of patients with Brugada syndrome and an implanted cardioverter-defibrillator

Introduction: Risk stratification of Brugada syndrome (BrS) remains controversial and recommendations for an implantable cardioverter-defibrillator (ICD) are not well established. The objective of this study was to assess the long-term prognosis of BrS patients with an ICD.

Methods and results: Of 55 consecutive patients with BrS assessed between April 2002 and October 2012, 36 (mean age 41.7 ± 13.8 years; 81.8% male) underwent ICD implantation. Nineteen (52.8%) were asymptomatic, 11 (30.6%) had previous history of syncope (arrhythmic cause suspected in eight) and six (16.7%) had aborted sudden cardiac death (SCD). Spontaneous type 1 electrocardiographic (ECG) pattern was present in 25 (69.4%) patients and electrophysiological study (EPS), performed in 26 (72.2%), was positive in 22 (84.6%). During a mean follow-up of 74 ± 40 months (>5 years in 72% of cases), seven (19.4%) patients had appropriate shocks (annual event rate 2.8%). These patients most frequently had aborted SCD (54.1% vs. 6.9%; p=0.008) and nonsustained ventricular tachycardia (57.1% vs. 10.3%; p=0.016) during follow-up. Spontaneous type 1 ECG pattern, syncope and positive EPS were not significantly associated with appropriate shocks. Multivariate analysis revealed that aborted SCD was an independent predictor of appropriate shocks (HR 8.07, 95% CI 1.58-41.2; p=0.012). ROC curve analysis demonstrated that aborted SCD had moderate discriminatory power to predict appropriate shocks (AUC 0.751), with sensitivity of 57% and specificity of 93%. In terms of ICD-related complications, eight (22.2%) patients had inappropriate shocks during the follow-up period, mainly due to sinus tachycardia (five patients); one patient had lead infection and another had a lead fracture.

Conclusion: In this population of BrS patients with ICD, the long-term rate of appropriate shocks was 2.8%/year. Aborted SCD was associated with a higher risk of appropriate shocks, whereas syncope and spontaneous type I ECG pattern did not predict this event.